The growth of most submarine vegetation, such as algae, is harmful to the ecology of a body of water. It substantially contributes to the eutrophication of the body of water and this eventually leads to the extinction of all life from the water and to the formation of a slimy overgrowth. This renders the water unsightly and useless for practically any purpose. Harvesting of submarine vegetation growth, along with the building of sewers to prevent nutrient run-off into the water, are among the principal measures to save bodies of water from eutrophication.
The harvesting of submarine vegetation is carried out practically exclusively with clumsy, inefficient machinery which is generally very large and provides its own flotation. The operator of the large machinery usually rides the machine itself in the water. Alternative means for the removal of submarine vegetation growth includes various toxic chemicals, but these are expensive and have their own dangerous ecological side effects. There is no simple, relatively small machinery available to small riparian owners for the removal of submarine vegetation growth.
There are various smaller submarine vegetation cutting devices disclosed in the prior art, however, none of them appear to have been commercially realized. U.S. Pat. No. 3,499,271 shows an underwater weed cutter attachment for the drive shaft of an outboard motor and the propeller of the motor is, in turn, attached to the drive shaft protruding from the cutter attachment. Two sets of flat reciprocating blades are powered from the drive shaft of the outboard motor through a power transmission.
U.S. Pat. No. 3,601,956 discloses a hand operated underwater cutter in which double edged blades are attached to opposite sides of a header which is mounted at the end of a shaft which permits the immersion of the header and the blades into the water. The blades pivot away from the direction of movement to permit uncut weeds from slipping out of the end of the blade to prevent it from fouling.
French patent No. 1,051,916; and Swiss patents Nos. 125,643 and 126,354 also describe simple, rudimentary underwater weed cutting devices or features thereof.